To code or not to code, that is the question...
I changed my battery (MKIII Octy) last Monday. The new one was fully charged and after a minute or two all the usual warnings you get when you disconnect the battery disappeared and the Start-Stop system cane back to life from the off. Having researched whether or not it's necessary to code the new battery to the car the jury was still out. Some said (as my experience suggests) that provided you replace like with like i.e. AGM with AGM there's no need to code it. However, given that I was an OBD Eleven early adopter I have the (now subscription based) Pro (VAG) version for life as it came with the c,€33 dongle back then, my OCD couldn't cope with not coding it so, come Saturday, I had to do it but I don't think I'd bother subscribing to any of the OEM level diagnostic providers unless it obviously needed to be done. Interestingly some of those who suggested it does need to be done said the Start-Stop system wouldn't work without coding, that's clearly either incorrect or situation specific.
In any event, the coding is simple enough. All that needs to be changed is the serial number... you can enter any 10 digit number you want provided it's different to the one already coded . You can also change the power rating although most fora contributors suggest that's only necessary if it differs significantly e.g. by 10+%. Mine didn't differ significantly as it's 70AH whereas the original was 68AH but my OCD made me change it regardless. You can also change the make - VAG code the original Exide as JCB as per it's BEM Code despite there being another code available for Exide. However if you can't find a code for your make there is an Unknown option or you can just leave it alone. I left mine alone 'cos if there is a BEM sticker on it it's not on the top and I didn't look for it before installing it and even my OCD can cope with the wrong make being coded! As always with VAG there is an oddity. When it comes to the Technology parameter AGM is coded as "Fleece" in Europe which is, apparently, a German/VAG/more descriptive term used for that technology. There is a "Binary - AGM" option that shouldn't be selected according to those in the know but others have said they used that with no issue.
